#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include<string.h>

int main()
{
    char title[5] = { 0 };
    gets(title);
    int i = 0;
    int len = strlen(title);
    int count = 0;
    for (i = 0; i < len; i++)
    {
        int a1 = *(title + i) >= 48 && *(title + i) <= 57;
        int a2 = *(title + i) >= 65 && *(title + i) <= 90;
        int a3 = *(title + i) >= 97 && *(title + i) <= 122;
        if (a1 || a2 || a3)
        {
            count++;
        }
    }
    printf("%d", count);
    return 0;
}